57:i 
dies buried in the countries of the north exhi- 
bits, were I not afraid of increasing* the number 
of geological dreams. 
The basalts of Regia, sketched on this plate, 
offer an undeniable proof of that identity of 
form, which is observed among the rocks of 
different climates. The mineralogical traveller, 
who casts a look over this ^drawing, finds in it 
the form of the basalts of the Vivarias, of the 
Euganean mountains, or of the promontory of 
Antrim in Ireland. The slightest circumstances 
observable in the columnar rocks of Europe are 
perceived in this group of the basalts of Mexico. 
So great an analogy of structure leads us to 
suppose, that the same causes have acted under 
every climate, and at very different epochas ; 
for the basalts covered with thonschiefer and 
compact limestone must be of a very different 
age from those, that repose on strata of coal and 
pebbles. 
The cascade of Regia is to the north-east of 
Mexico, at a distance of twenty- five leagues, 
between the celebrated mines of Real del 
Monte, and the thermal waters of Totoniico. 
A small rivet*, which moves the wheel of the 
mill for amalgamation at Regia, the construc- 
tion of which cost more than ten millions of 
livres, forces its way across the groups of ba- 
saltic columns ; the sheet of water that rushes 
down is considerable, but the fall is not above 
VOL. XIII. T 
